Mood stabilizers during pregnancy – significance of therapeutic drug monitoring

Introduction Using a mood stabilizer can be essential for pregnant women suffering from bipolar disorder to protect them from relapse. However, every prescription for psychotropic drugs during pregnancy must be subjected to a critical assessment of the benefits and risks for the mother and the embryo and/or fetus. Depending on the substance, intrauterine exposure to mood stabilizers is associated with different teratogenic risks, whereby the serum concentration of the substance can be decisive. As physiological changes during pregnancy can lead to changes in drug concentrations, therapeutic drug monitoring (TDM) may be indicated to minimize risk.

Methods The literature indexed on PubMed was searched for original observational studies, case reports, and case series that evaluated or described TDM of mood stabilizers during pregnancy.

Results Pregnancy-related changes in absorption, distribution, metabolism, and elimination are associated with significant and clinically relevant changes in plasma concentrations of mood stabilizers. This applies to varying degrees to lithium, lamotrigine, carbamazepine, and valproate, but also to the atypical antipsychotics used as mood stabilizers. While plasma concentrations of lithium and valproate decrease, they increase significantly for lamotrigine during pregnancy; the plasma concentrations of carbamazepine remain largely unchanged. Moreover, levels of most atypical antipsychotics used as mood stabilizers decrease during pregnancy.

Conclusion Since pregnancy-related physiological changes may result in significant and clinically relevant changes in plasma concentrations of mood stabilizers, optimal dose management during pregnancy is essential to reduce the risk of relapse. Therefore, therapy with mood stabilizers during pregnancy should be guided by TDM.

Conflict of Interest The author has no conflict of interest to declare.

Publication History

Article published online:
16 May 2022